Out Of Office Responders

[Tim Smith]

Had a quick look around on Google for this but no definitive answer. I 
am looking to incorporate some "Out Of Office" functionality with my 
dovecot/postfix set up. I need this to work with a variety of email 
clients if those clients support that functionality. Ideally, it would 
work "out of teh box" much in the same way that Outlook sets the "Out Of 
Office" message but I think this works because it may be a a MS Exchange 
server providing that functionality.

I notice that postfix comes with a program called "vacation". Is this 
something that can be configured by the client?